(1) Field of the Invention
The invention relates generally to the field of signal processing and more particularly to a system and method for rapidly detecting a moving target and determining its movement characteristics, such as range, bearing, speed and course in a noisy environment.
(2) Description of the Prior Art
Detection of a moving object, such as a target, and determination of its range, bearing, speed and course in an ocean environment, is a difficult task, particularly if the target is moving relatively noiselessly and it is desired to perform the detect as early as possible. Typically, acoustic sensors are used to detect acoustic energy (sound waves) emitted by a moving object and convert such energy to electrical signals, and complex signal processing operations are performed in connection with the electrical signals to isolate and provide the desired information. An ocean environment is generally very noisy, and so low-level acoustic signals typical of quietly-moving targets and the high level of ambient noise joint to provide a relatively low ratio of desired signal-to-noise in the electrical signal provided by the sensor, which makes early and accurate detection quite difficult. In current systems, signals that do not have a signal-to-noise ratios above a selected predetermined threshold value are ignored, in which case such signals are not available to provide information which may potentially be useful in characterising the motion of the target.